Horny Goat Weed
Horny goat weed (Epimedium) is marketed for sexual function. High-quality human evidence remains limited.
Overview
What is horny goat weed?
Horny goat weed (Epimedium) contains the bioactive flavonoid icariin, which primarily acts as a phosphodiesterase type 5 (PDE5) inhibitor, improving blood flow and erectile function.
Icariin also has anti-inflammatory, antioxidant, and immune-modulating effects, likely through multiple molecular pathways including nitric oxide signaling and suppression of inflammatory cytokines.
These mechanisms contribute to its traditional use as an aphrodisiac and potential cardiovascular support. Most evidence comes from animal and cell studies, warranting further human research.
Dosage
A typical dose of icariin, the active ingredient in horny goat weed, is 600-1,200 mg per day.
Effect graph
Subscribe to view effect graphs
Interactive visualisations of ranked conditions and clinical benefit with purchase guidance.
Already a subscriber? Sign in
Effect heatmap
Subscribe to view effect heatmaps
See effect size, evidence strength, and trust at a glance for every condition.
Already a subscriber? Sign in
SupplementDEX Database
2 conditions for and rated at least stars. All purchase bands. No minimum star filter.
Subscribe to access the SupplementDEX Database
Read this and 2,600+ other evidence reviews on our practitioner plan.
Already a subscriber? Sign in
Database Snapshot
Most horny goat weed research is concentrated in a handful of conditions.
- Osteoporosis accounts for 2 of 3 studies (67%).
- Erectile dysfunction accounts for 1 of 3 studies (33%).
- Sparse coverage remains for Osteoporosis, Erectile dysfunction.
Safety
Oral horny goat weed is safe and well tolerated, but may cause abdominal discomfort in some people.
In women, horny goat weed may increase estrogen.
Frequently Asked Questions
References
Sources3 references
SupplementDEX uses only high-quality sources to determine supplement effectiveness.
1.SupplementDEX Database: Erectile dysfunction — Efficacy and Safety of Common Ingredients in Aphrodisiacs Used for Erectile Dysfunction: A Review2020
A review of common aphrodisiac ingredients for erectile dysfunction concluded evidence remains limited and poorly studied for most supplements.
SupplementDEX Database · Osteoporosis
2 references2.SupplementDEX Database: Osteoporosis — Epimedium for Osteoporosis Based on Western and Eastern Medicine: An Updated Systematic Review and Meta-Analysis2022
An updated systematic review and meta-analysis (1,017 participants) found Epimedium supplementation improved bone mineral density in osteoporosis across included RCTs.
3.SupplementDEX Database: Osteoporosis — Epimedium-derived phytoestrogen flavonoids exert beneficial effect on preventing bone loss in late postmenopausal women: a 24-month randomized, double-blind and placebo-controlled trial2007
In 50 late postmenopausal women over 24 months, Epimedium-derived phytoestrogen flavonoids (60 mg/day) prevented bone loss without endometrial hyperplasia versus placebo.